Patent GB-813543-A (GB)
Title: Benzimidazolylstilbenes
Filed: 1956-04-13
Abstract: Benzimadazolylstilbenes of formula: <FORM:0813543/III/1> in which (a) R1, R1, R3 and R4 are hydrogen atoms, alkyl groups containing 1-4 carbon atoms, alkoxy groups containing 1-4 carbon atoms or halogen atoms, and Y1 and Y2 are hydrogen atoms, alkyl groups containing 1-6 carbon atoms, hydroxyalkyl groups containing 2-6 carbon atoms, hydroxy oxaalkyl groups containing 3-15 carbon atoms, carboxyalkyl groups containing 2-6 carbon atoms, cyanoalkyl groups containing 3-6 carbon atoms, monocyclic aralkyl groups containing 7-11 carbon atoms; and also compounds in which (b) R1, R2, R3 and R4 are as above, Y1 is a hydrogen atom, an alkyl group containing 1-6 carbon atoms, a carboxyalkyl group containing 2-6 carbon atoms, a cyanoalkyl group containing 3-6 carbon atoms, allyl, methallyl, a monocyclic aralkyl group containing 7-11 carbon atoms, an acyloxyalkyl group in which the alkyl group contains 2-6 carbon atoms, 2-acyloxy-3-sulphopropyl or an acyloxy-oxaalkyl group in which the oxaalkyl group contains 3-15 carbon atoms; and Y2 is an acyloxyalkyl group in which the alkyl group contains 2-6 carbon atoms, 2-acyloxy-3-sulphopropyl or an acyloxy-oxaalkyl group in which the oxaalkyl group contains 3-15 carbon atoms, the acyloxy groups in Y1 and Y2 being defined as HOOC-A-COO- where A is the residue of an aromatic 1,2-dicarboxylic acid containing 8-20 carbon atoms, an aliphatic 1,2-dicarboxylic acid containing 4-22 carbon atoms or a cycloaliphatic 1,2-dicarboxylic acid containing 7 or 8 carbon atoms; are used as whitening and brightening agents in conjunction with one or more suitable dispersing agents, for instance soap or an amionic or non-ionic detergent, such as an alkyl sulphate, alkylbenzene sulphonate, or alkylmercaptopolyethoxyethanol.  Dispersions may be formed by dissolving the compound in a suitable solvent, such as N,N-dimethylformamide, alkaline aqueous alcohol or glacial acetic acid, and mixing the solution thus obtained with an aqueous soap or detergent solution, but a preferred method of using the compounds is by incorporating them into solid or liquid soaps and detergents. Sodium sulphate and tripolyphosphate may also be incorporated.ALSO:The invention comprises benzimidazolylstilbenes of formula: <FORM:0813543/IV (b)/1> in which (a) R1, R2, R3 and R4 are hydrogen atoms, alkyl groups containing 1-4 carbon atoms, alkoxy groups containing 1-4 carbon atoms or halogen atoms and Y1 and Y2 are hydrogen atoms, alkyl groups containing 1-6 carbon atoms, hydroxyalkyl groups containing 2-6 carbon atoms, 2-hydroxy-3-sulphopropyl, hydroxy-oxaalkyl groups containing 3-15 carbon atoms, carboxy alkyl groups containing 2-6 carbon atoms, cyanoalkyl groups containing 3-6 carbon atoms, monocyclic aralkyl groups containing 7-11 carbon atoms, e.g. halobenzyl, alkylbenzyl, or alkoxybenzyl, allyl or methallyl groups; and, also, compounds in which (b) R1, R2, R3 and R4 are as above, Y1 is a hydrogen atom, an alkyl group containing 1-6 carbon atoms, a carboxy alkyl group containing 2-6 carbon atoms, a cyanoalkyl group containing 3-6 carbon atoms, allyl, methallyl, a monocyclic aralkyl group containing 7-11 carbon atoms, an acyloxy alkyl group in which the alkyl group contains 2-6 carbon atoms, 2-acyloxy - 3 - sulphopropyl or an acyloxy - oxaalkyl group in which the oxaalkyl group contains 3-15 carbon atoms; and Y2 is an acyloxy-alkyl group in which the alkyl group contains 2-6 carbon atoms, 2-acyloxy-3-sulphopropyl or an acyloxy-oxaalkyl group in which the oxaalkyl group contains 3-15 carbon atoms the acyloxy groups in Y1 and Y2 being defined as HOOC-A-COO, where A is the residue of an aromatic 1.2-dicarboxylic acid containing 8-20 carbon atoms, an aliphatic 1.2-dicarboxylic acid containing 4-22 carbon atoms or a cycloaliphatic 1.2-dicarboxylic acid containing 7 or 8 carbon atoms.  Compounds of type (a) are prepared from the appropriately ortho-substituted bis-anilides of 4.41-stilbene dicarboxylic acids.  The compounds in which Y1 and Y2 are both hydrogen may be prepared by cyclisation of a bis-(orthoaminoanilide) of a 4.41-stilbene dicarboxylic acid by heating it in acidic conditions.  The bis-(ortho-aminoanilide) materials are obtained by reduction of the corresponding bis-(ortho-nitroanilides) which are obtained by heating one mol. of 4.41-stilbene dicarbonyl chloride with 2 mols. of the appropriate orthonitroaniline, preferably in a solvent, e.g. chlorbenzene, and in the presence of an acidaccepting medium, e.g. an N.N-dialkylaniline. Using this process the following compounds may be prepared: 4.41-bis-[4 (or 7)-methoxy-benzimidazol-2 - yl)] stilbene, 4.41 - bis [4 (or 7) ethoxybenzimidazol - 2 - yl)] stilbene, 4.41 - bis - [5 (or 6) isopropoxybenzimidazol - 2 - yl] stilbene, 4.41 - bis - (5.6 - dimethoxybenzimidazol-2 - yl) stilbene, 4.41 - bis - (5.6 - dibutoxybenzimidazol - 2 - yl) stilbene, 4.41 - bis - [4.5.7 (or 4.6.7) trimethoxybenzimidazol - 2 - yl] stilbene, 4.41 - bis - [4 (or 7) methylbenzimidazol - 2 - yl] stilbene, 4.41 - bis - [5 (or 6) tert. - butylbenzimidazol - 2 - yl] stilbene, 4.41 - bis - (5.6 - dimethylbenzimidazol - 2 - yl) stilbene, 4.41 - bis(4.5.6.7 - tetramethylbenzimidazol - 2 - yl) stilbene, 4.41 - bis - [5 (or 6) ethylbenzimidazol-2 - yl) stilbene, 4.41 - bis - [5 (or 6) chlorobenzimidazol - 2 - yl] stilbene, 4.41 - bis - [5 (or 6)-fluoro - 4.41 - bis - (benzimidazol - 2 - yl) stilbene, 4.41 - bis - [4.6 (or 5.7) dibromo - 4.41-bis - (benzimidazol - 2 - yl) stilbene, 4.41 - bis-(4.5.6 (or 5.6.7) trichloro - 4.41 - bis - (benzimidazol - 2 - yl) stilbene, 4.41 - bis - [6 - methoxy - 5 - fluoro (or 5 - methoxy - 6 - fluoro)-4.41 - bis - (benzimidazol - 2 - yl)] stilbene, 4.41-bis - [4 - bromo - 6.7 - methylenedioxy - (or 7 - bromo - 4.5 - methylene dioxy) 4.41 - bis-(benzimidazol - 2 - yl)] stilbene and 4.41 - bis-[5 - methoxy - 6 - methyl - (or 5 - methyl - 6-methoxy) - 4.41 - bis - (benzimidazol - 2 - yl)] stilbene.  Those compounds in which Y1 and Y2 are both hydrogen may be reacted with alkylating agents to yield N-mono- and symmetrical or unsymmetrical N.N1-di-(alkyl or substituted alkyl) derivatives.  The reaction is carried out by heating the reactants.  Suitable alkylating agents include, for example, esters of strong organic and inorganic acids having the formula Z-An in which Z is an alkyl group containing 1-6 carbon atoms, a hydroxyalkyl group containing 2-6 carbon atoms, 2-hydroxy-3-sulphopropyl, a hydroxy oxa-alkyl group containing 3-15 carbon atoms, a carboxy-alkyl group containing 2-6 carbon atoms, a cyano-alkyl group containing 3-6 carbon atoms, or a monocyclic aralkyl group containing 7-11 carbon atoms and An is the anion of a strong acid, e.g. sulphuric, toluene sulphonic or a hydrohalic acid. The N-monoalkylated compounds (in which either Y1 or Y2 is hydrogen) are obtained by heating one mol. of the alkylating agent with one mol. of the 4.41-bis-(benzimidazol-2-yl) stilbene.  If the N.N1-dialkylated compound is required at least 2 mols. of the alkylating agent should be used.  An alternative method of preparing the N-(2-cyanoalkyl) and N.N1-di-(2-cyanoalkyl) compounds of the formula given above is by reacting an alkyl nitrile with the N.N-unsubstituted compound.  These cyano compounds may be hydrolysed to give the corresponding 2-carboxylalkyl compounds. Benzimidazolylstilbenes of the formula given above and containing one or more alcoholic hydroxy groups in Y1 and Y2 may be converted to carboxy esters of dicarboxylic acids to give compounds of type (b). They are prepared by reacting the cyclic anhydrides of the appropriate acids with the hydroxy-benzimidazolylstilbenes.  Suitable anhydrides are, for example, those of phthalic, halophthalic, phenylphthalic, 1.2 - cyclohexane dicarboxylic, 1.2 - cyclopentane dicarboxylic, 4-cyclohexene-1.2-dicarboxylic, succinic, alkyl succinic, alkenyl succinic, aralkylsuccinic, maleic, alkyl maleic and aralkyl maleic acids.  The reactants are heated together advantageously in a solvent and in the presence of an organic base. A mixture of anhydrides may be used.  In the examples details are given of the preparation by the previously described methods of compounds of the above formula in which R1, R3, R4 are hydrogen, R2 is hydrogen, methyl, chlorine or methoxy and Y1 and Y2 are the same or different and are hydrogen, methyl, -CH2COOH, -CH2CH2CN, -CH2CH2COOH, o - chlorphenyl, -CH2-CH = CH2, -CH2CH2OH, -CH2CHOH-CH2OCH2CH2OH, -CH2-CHOH-CH2-O-CH2 - CH2O - CH2 - CHOH - CH2OCH2\t -CH2OH, -CH2-CHOH-CH2OCH2CH2OCH2 -CH2OH, -CH2CHOHCH2SO3H, -CH2-CHOH-CH2OH, -CH2-CHOHCH2OCH2\t -CHOHCH2OH, - CH2CH2OCH2CH2OH, - CH2CH2COOCH = CHCOOH, - CH2CH2 -OCH2CH2COOCH = CHCOOH, oCOOH-C6H4 -COOCH2CH2 -, oCOOH - C6H4-COOCH2CH2 - OCH2CH2 -, 3 - and 4 - Cl -C6H4COOCH2CH2 3 - and 4 - Cl - C6H4COOCH2CH2OCH2CH2 -, 3.4.5.6 - Cl4 - 2-HOOC - C6 - COOCH2CH2 -, 3.4.5.6 - Cl4 - 2 - COOH - C6 - COO - CH2CH2 - O-CH2CH2 -, COOH - CH2CH2 - COO-CH2CH2 -, COOH - CH2CH2 - COO-CH2CH2 - O - CH2CH2 -, COOH - C2H3 (C12H23), COOCH2 CH2 -, COOH - C2H3 (C12H23)COOCH2CH2 -, 2 - COOH - C6H10 COOCH2CH2 -, and 2 - COOHC6H10-COO-CH2CH2OCH2CH2 -.ALSO:New benzimadazolylstilbenes of formula <FORM:0813543/IV (c)/1> in which (a) R1, R2, R3 and R4 are hydrogen atoms, alkyl groups containing 1-4 carbon atoms, alkoxy groups containing 1-4 carbon atoms or halogen atoms and Y1 and Y2 are hydrogen atoms, alkyl groups containing 1-6 carbon atoms, hydroxyalkyl groups containing 2-6 carbon atoms, hydroxy oxaalkyl groups containing 3-15 carbon atoms, carboxyalkyl groups containing 2-6 carbon atoms, cyanoalkyl groups containing 3-6 carbon atoms, monocyclic aralkyl groups containing 7-11 carbon atoms, e.g. halobenzyl, alkylbenzyl or alkoxybenzyl, allyl or methallyl groups; and also compounds in which (b) R1, R2, R3 and R4 are as above, Y1 is a hydrogen atom, an alkyl group containing 1-6 carbon atoms, a carboxyalkyl group containing 2-6 carbo